Fish of Admiralty Bay (King George Island,South Shetland Islands,Antarctica)

Summary The species composition of the ichthyofauna of Admiralty Bay, King George Island was determined from results of sampling using bottom trawls, gill-nets and long-lines. Thirty-five species from 24 genera and 10 families (Table 1) were found. The number of species increased with depth (e.g. 7 species at 100 m, 14 species at 255 m and 21 species at 540 m), a tendency characteristic of Antarctic waters. In the bay, the catch rate obtained with a bottom trawl (greater than 30 kg/h) was roughly ten times lower than the catch rate using the same gear on the shelf around the Island. Notothenia gibberifrons was the dominant species in all trawls. The majority of these fish (about 95%) were immature juveniles (Table 4). Younger fish were found to inhabit shallower waters (Fig. 1). The majority of the fish of species Notothenia coriiceps neglecta, Notothenia rossii marmorata, Notothenia nudifrons, Trematomus newnesi and Trematomus bernacchii preferred waters about 255 m deep. Fourteen specimens of a previously undescribed species of the genus Psilodraco (currently being described by H. DeWitt) were caught in the bay within the 146 to 540 m depth range. The rare zoarcid, Lycenchelys aratrirostris, was also caught in Admirality Bay; previously this species had only been reported from the Elephant Island region. In the case of Trematomus newnesi, the occurrence of scales in the interorbital space was noted (Fig. 2), an observation which verifies this feature as a distinct taxonomical criterion for this species.     

Trophic relationships between the kelp gull and the Antarctic limpet at King George Island (South Shetland Islands, Antarctica) during the breeding season

The diet of the kelp gull (Larus dominicanus), its foraging behaviour and the consumption rates on the Antarctic limpet (Nacella concinna) were studied during austral spring and summer 1992/1993 and 1993/1994 at Potter Peninsula, King George Island, Antarctica. Prey information was obtained by collecting 237 pellets, foraging behaviour was observed by focal and instantaneous scan samplings, and consumption rate was estimated by means of weekly sampling of limpets found in 5 nests and their respective middens. Limpets were the most important prey followed by scavenged prey (penguin and seal carcasses), amphipods, snails, fish and euphausiids. Foraging gulls spent 51% of the time searching for limpets, 10% moving between foraging areas, 9% in catching effort and 15% handling prey. The number of gulls observed searching for limpets was inversely correlated with the tidal height. In the diet limpets provide 102.3, 159.4 and 188.1 kJ gull⁻¹ day⁻¹ during incubation, hatching and brooding respectively; these values range between 15 and 27%, with a maximum of 40%, of the basic daily energy requirements of kelp gulls. Total consumption rate estimations for the whole population of gulls at Potter Peninsula reached between 3400 and 4800 limpets day⁻¹, which represents approximately 10–14% of the total annual limpet mortality. Received: 25 March 1996 / Accepted: 26 August 1996     

Lactation costs in southern elephant seals at King George Island,South Shetland Islands

Labelled-water methodology was used to quantify energy costs and energy transfer efficiency in 18 mother-pup pairs of southern elephant seals (Mirounga leonina) during lactation. During the lactation period, mothers lost a mean mass of 227±47 kg. Mass loss included 22% of the protein, 60% of the fat, and 51% of the energy in the mothers body upon arrival. Total body-energy reserves at parturition explained 69% of the variation in the total lactation costs and 50% of the variation in the pups body energy at weaning. On average, pups retained 48% of the mass, 49% of protein, 53% of fat and 51% of energy lost by their mothers. Greater, fatter females showed a decrease in the efficiency of energy and fat transfer and, at the same time, an increase in the efficiency of protein transfer. This may be due to an increased use of protein as metabolic fuel, as fat demands for milk production increase. There was no evidence that greater total lactation costs influence the ability of mothers to produce a pup in the next breeding season.     

Biodiversity of periphytic cyanobacteria and algae assemblages in polar region: a case study of the vicinity of Arctowski Polish Antarctic Station (King George Island,Antarctica)

Biodiversity and Conservation - This study was carried out on periphytic cyanobacteria and algae assemblages of microbial mats in streams and small water bodies during the Antarctic summer of 2019...     

Vegetation Types,Community Species Diversity and Conservation of Southern Fildes Peninsula (King George Island,South Shetland Islands) Antarctic

The vegetation in Southern Peninsula (including Ardley Island) was classified according to the composition of species (especially dominant species), physiognomy and structure, and ecology factor, into tundra, meadow, marsh and aquatic vegetation; among which the formation and association were described. The formation and distribution of these communities were dependent on the water supply and the stability of the substrata. The paper discusses also the distributional pattern of vegetation from coast to hill top, characteristics of communities, comparative study on the species number, evenness and diversity among each formation and among different habitat, and some suggestions on vegetation conservation was also attempted.     

Typology of lentic water bodies at Potter Peninsula (King George Island, Antarctica) based on physical-chemical characteristics and phytoplankton communities

During austral summer 1995/1996, 26 ultraoligotrophic to hypereutrophic ponds and lakes on Potter Peninsula (King George Island, Antarctica) were characterized on the basis of abiotic factors and the phytoplankton community. The influence of vegetation and animal presence in the catchment, morphometric variables of the water bodies and their proximity to the sea on composition and abundance of phytoplankton was also considered. Results of a Principal Component Analysis show that the characteristics of each catchment strongly influenced the abiotic parameter accounting for the obtained lake and pond ordination. In particular, five groups of water bodies were clearly defined primarily based on nutrients and suspended solid concentrations, and to a lesser extent on pH and conductivity. These groups could be classified into two assemblages distributed along a phytoplankton biomass gradient, which is regulated by the light availability in one case and by nutrient concentrations in the other. Among 140 algal taxa registered, 3 were new records for Antarctica and 18 taxa were new records for Potter Peninsula. Bacillariophyceae was the dominant class in terms of species number and density. Chlorophyta and Cyanobacteria were subdominant. The tychoplanktonic habit was the best represented in almost all lakes. Accepted: 3 June 2000     

Analysis of trace metals in the Antarctic host-parasite system Notothenia coriiceps and Aspersentis megarhynchus (Acanthocephala) caught at King George Island,South Shetland Islands

Concentrations of the elements Al, Ag, As, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Sr were analysed by high-performance quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) in the acanthocephalan Aspersentis megarhynchus and in different tissues of its final host, Notothenia coriiceps. Infected fish were sampled at King George Island, South Shetland Islands, Antarctica. Most of the elements were found at significantly higher concentrations in the acanthocephalan than in muscle, liver and intestine of its host. Only Fe was concentrated in fish liver to a significantly higher level than in the parasite. Compared with the host tissues, the highest accumulation rates in A. megarhynchus were found for Pb, Cd, Ag, Ni and Cu. The acanthocephalans showed very high Ag and Pb levels, whereas the concentrations in the fish tissues were close to the detection limit. This study is the first proof that the enormous heavy-metal accumulation capacity reported for acanthocephalans from freshwater fish also occurs in acanthocephalans parasitizing marine fish. Consequently, acanthocephalans can be used to assess the occurrence and availability of even the lowest metal concentrations in all kinds of aquatic habitats, including remote areas such as the Antarctic.     

Fish diet of the Antarctic fur seal,Arctocephalus gazella,in summer,at Stranger Point,King George Island,South Shetland Islands

 In February 1992, 34 faecal samples from non-breeding male Antarctic fur seals, Arctocephalus gazella, were collected at Stranger Point, King George Island, South Shetlands. Fish constituted an important part of the diet, occurring in 90% of those scats containing prey remains. From 1162 otoliths found in the faeces, 1086 were identified to at least family level. Myctophids and nototheniids represented together almost 90% of the fish eaten. The dominant species were Gymnoscopelus nicholsi, Pleuragramma antarcticum and Electrona antarctica, contributing 33.3%, 30.8% and 12.0% of the otoliths respectively. The standard length of these three species was estimated from otoliths with little or no signs of erosion. This study showed that fur seals fed mainly on pelagic fish species that are often associated with krill. These findings are corroborated by fur seal diving patterns. Received: 7 October 1994/Accepted: 5 October 1995     

Soil properties and distributions of invertebrates and bacteria from King George Island (Arctowski Station), maritime Antarctic

Soils of the Admiralty Bay region at King George Island, maritime Antarctic are described and analysed for invertebrates and microorganisms. Results showed a great variety of soils: cambisols, umbrisols, regosols, podzols, leptosols, gleysols and relic ornithogenic soils were found. Surface layers, especially of cambisols, umbrisols and podzols, showed a diverse fauna, governed by nematodes, collemboles and mites. The bacterial flora is analysed for total counts and biomass distribution in different layers using epifluorescence microscopy. Influences of soil organic matter can be described by different patterns of mean bacterial cell volumes related to soil cover and depth distributions. Received: 21 February 1997 / Accepted: 28 April 1997     

Benthic megafauna of the nearshore zone of Martel Inlet (King George Island, South Shetland Islands, Antarctica): depth zonation and underwater observations

The benthic megafauna from the soft bottoms of the shallow coastal zone of Martel Inlet (Admiralty Bay, King George Island, South Shetland Islands, Antarctica) was studied during three austral summers (1989/1990, 1990/1991 and 1994/1995) in relation to the bathymetric features. Surveying and sampling, based on specimen counting and underwater observations, were undertaken by scuba-diving at depths down to 25 m. The depth zonation appears to be influenced by the nature of the substrate and especially by the action of the ice. The multiple action of ice flows prevents the occurrence of sessile forms in the shallower areas, where a low-diversity community, dominated by motile animals, was found. In the area around 18 m in depth, the action of icebergs generated faunistic and sedimentary patches of impacted and non-impacted areas. The more stable conditions prevailing below depths of 20–25 m allowed the establishment of a more diversified epifauna, including many sessile forms. The interannual differences observed in the densities of the mobile isopod Serolis polita may be associated with the summer period when the sampling was undertaken. Accepted: 1 March 2000     

Provisioning and growth in chicks of Wilson's storm-petrels (Oceanites oceanicus) on King George Island, South Shetland Islands

We present data on chick growth and chick feeding in Wilson's storm-petrel (Oceanites oceanicus) in a colony on King George Island, South Shetland Islands. Chicks were repeatedly weighed and the weight differences over 24 h were corrected for metabolic loss in order to obtain an estimation of meal sizes. Chicks were fed on 93% of the nights (n=688 nights). The average meal size for a single feeding was 8.5 g. Chicks received on average 1.2 feedings per night. These results are compared with data for this species from other locations. There was a trend for increased meal sizes from northern to southern populations, parallel to an increase in the adult mass, indicating that Wilson's storm-petrels carry optimal meal sizes according to their body size and may take advantage of increased food abundance by increasing feeding frequencies. We describe chick growth and discuss the influence of egg size, hatching date and feeding frequency on chick growth. The egg size had a positive influence on tarsus growth and body mass of chicks. Later-hatched chicks started wing growth and finished mass growth at a younger age and reached lower peak masses, indicating that late chicks may adapt to the restricted breeding season in their Antarctic breeding grounds by a more rapid development, but will fledge with a lower degree of development and less resources. Accepted: 22 May 2000     

The benthos off King George Island (South Shetland Islands,Antarctica): further evidence for a lack of a latitudinal biomass cline in the Southern Ocean

The benthic fauna off King George Island (South Shetland Islands, Antarctica) was investigated during "Polarstern" expedition ANT XV/3 in March 1998. Samples were taken along two cross-shelf/slope transects both north (Drake Passage) and south of the island (Bransfield Strait, off Potter Cove) at water depths ranging from 130 m to 2,000 m. For a quantitative inventory, a multibox corer was used at nine stations to collect mostly infaunal macrobenthos; at seven stations, seabed photography was employed concomitantly to survey the epibenthic megafauna. Macrofauna abundances ranged from 730 ind. m^–2 at 2,000 m to >14,000 ind. m^–2 at 100 m; biomass values varied between about 50 g wet mass m^–2 (6 g ash-free dry mass m^–2) at 2,000 m and about 950 g wet mass m^–2 (about 90 g ash-free dry mass m^–2) at 200 m. Densities were dominated everywhere by polychaetes, followed by bivalves, crustaceans and ophiuroids; in terms of biomass, krill and holothurians surpassed polychaetes at some stations. No significant differences between the northern and the southern transects in total abundance and biomass were obvious. Megafauna abundances were clearly higher south of King George Island, totalling about 110–150 ind. m^–2 on the shelf (235–330 m) and about 50 ind. m^–2 at the continental slope (750 m), whereas along the northern transect they reached values of only 21–31 ind. m^–2 on the shelf (130–430 m) and decreased at the continental slope (950 m) to about 5 ind. m^–2. A brittle star, Ophionotus victoriae, strongly dominated the southern-shelf epibenthos, with relative abundances of 70–95% and a biomass of about 40–80 g wet mass m^–2 (about 4–7 g ash-free dry mass m^–2), but was numerically less important at the slope (5%) where ammotheid pycnogonids prevailed (80%). Macro- and megabenthos distribution patterns were characterized by a pronounced shelf-slope gradient – in standing stock as well as in faunistic composition – but this resemblance was statistically not significant. This finding indicates that the spatial distributions of macrobenthos and megabenthos are primarily determined by a depth-dependent factor, most probably food supply, but apparently respond differently to secondary driving forces, possibly seabed features. Our results provide further evidence for the notion that there is no distinct latitudinal gradient in benthic abundance and biomass in the Southern Ocean between the South American Magellan region and high-Antarctic waters of the Weddell Sea.     

Prey size selectivity by kelp gulls on Antarctic limpets at King George Island, Antarctica

The present study was performed at Potter Peninsula (King George Island, Antarctica) with the following goals: (1) to assess the size selection of kelp gulls on Antarctic limpets during the chick-rearing period, and (2) to evaluate the degree of accuracy in the use of populational abundance and size-frequency distribution as an indicator of prey availability. The average size of limpets available to kelp gulls was significantly smaller than that of the population as a whole and those actually consumed by gulls. The odds ratio revealed a strong selectivity for large limpets, when available and consumed sizes were compared. However, only a proportion of the limpets present was available to gulls. These differences clearly show that using abundance information as an indicator of a resource importance can lead to substantial errors in ecological interpretations. Accepted: 21 November 1998     

Distribution patterns in the biomass of macrozoobenthic communities in Admiralty Bay (King George Island, South Shetlands, Antarctic)

The distribution patterns of macrozoobenthic communities as shown by the biomass of the higher taxa were investigated in Admiralty Bay. Material was collected at depths ranging from 4 to 500 m (102 quantitative samples), representing the full depth range of this basin and including areas characterized by the different levels of glacial influence. Five community groups were distinguished by multivariate analysis (clustering, MDS) based on the Bray--Curtis similarity index. In the Ezcurra Inlet, the area characterized by intensive glacial processes resulting in a high sedimentation rate, the distribution of biomass was not depth related, but was associated with the intensity of glacial disturbance along the axis of the fjord. The innermost part of this fjord, which receives strong outflows from glaciers, had a low biomass value (2.9 g/0.1 m²) and was dominated by polychaetes. The middle part of the fjord which is not so heavily disturbed had higher biomass values (46.1 g/0.1 m²) due to the dominance of bivalves. A clear depth gradient of biomass distribution was observed in bottom areas located far from glaciers, in the central basin of the bay, with three zones within the depth ranges 4–30, 40–380, and 400–500 m. The highest mean biomass values (92.5 g/0.1 m²) were found in the middle sublittoral (40–380 m) dominated by ascidians. In the shallow and deep assemblages, the biomass was lower (33.8 g/0.1 and 30.9 g/0.1 m² respectively), most probably associated with the ice disturbance in the shallows and lower food supply in the deepest part of the shelf.     

Abundance and biomass estimates of the benthic fauna in Admiralty Bay,King George Island,South Shetland Islands

Summary Quantitative benthic samples were collected along three transects in Admiralty Bay, King George Island, South Shetlands. At each of a total of 18 stations, between 15 and 250 m depth, we took 3 replicate samples with a van Veen grab. Animals collected were classed into major groups. Abundance and biomass per m² was calculated for each sampling site. Considerable population densities and high biomass values were found. Most abundant groups were Bivalvia, Polychaeta and Amphipoda, whereas the largest part of the biomass was due to Ascidiacea, Ophiuroidea, Echinoidea, Polychaeta and Bivalvia. The maximum abundance recorded was 36,000 ind m^-2 while the average was approximately 6500 ind m^-2. Maximum biomass was over 2400 g m^-2 with an average of ca. 700 g m^-2. The contribution to the total biomass by groups such as the Oligochaeta, Cumacea and Tanaidacea was higher in the inner shallow part of Admiralty Bay (Ezcurra Inlet) than in the deeper areas of the bay. Our results confirm the reports on an unusually high density and biomass of the Antarctic sublittoral benthic fauna. Sessile suspension feeders belonging to the Bivalvia, Ascidiacea, sedentary Polychaeta, and vagile scavengers of the Ophiuroidea, Amphipoda and errant Polychaeta are the most significant groups in the Antarctic Ecosystem. The total benthic biomass in Admiralty Bay, based on the present preliminary quantitative data, was estimated to be over 600,000 t. This value is probably still an underestimate.     

Lichen flora around the Korean Antarctic Scientific Station, King George Island, Antarctic

As part of the long-term monitoring projects on Antarctic terrestrial vegetation in relation to global climate change, a lichen floristical survey was conducted around the Korean Antarctic Station (King Sejong Station), which is located on Barton Peninsula, King George Island, in January and February of 2006. Two hundred and twenty-five lichen specimens were collected and sixty-two lichen species in 38 genera were identified by morphological characteristics, chemical constituents, TLC analysis and ITS nucleotide sequence analysis.     

Vegetation of Barton Peninsula in the neighbourhood of King Sejong Station (King George Island,maritime Antarctic)

Plant communities were studied on Barton Peninsula around King Sejong Station on King George Island, maritime Antarctic. The objective of this study was to document the occurrence and distribution of plant assemblages to provide the bases for monitoring the effects of environmental changes and human impact on the vegetation of this area. Approximately 47% of the investigated area was covered by vegetation. Crustose lichens showed the highest mean cover (21%) among vegetation components. The total mean cover of the four dominant taxa, together with the other three major subdominant components, i.e., Usnea spp., Andreaea spp. and Sanionia georgico-uncinata, was 78.2% of the total cover of all the species. Lichen cover and species diversity increased with altitude and the time of exposure from snow. Lichens contributed substantially more to the increased species density and diversity than did bryophytes. Ten plant communities were recognized within the study area. All of them belong to the Antarctic cryptogam tundra formation; they were grouped into four subformations: fruticose lichen and moss cushion subformation, crustose lichen subformation, moss carpet subformation and moss hummock subformation. The moss turf subformation was not found on this region. The Antarctic herb tundra formation was also not found; however, the populations of both Antarctic vascular plants have rapidly expanded around Barton Peninsula in recent years, which may allow development of the Antarctic herb tundra formation in the future.